Amir Khan’s fight Saturday against Zab Judah a proving ground

Amir Khan has showed his heart, opened his wallet and now he will be required to prove his ring intelligence.

Khan, the 24-year-old World Boxing Assn. light-welterweight champion, returns to the Mandalay Bay Events Center in Las Vegas on Saturday, when he will meet veteran Zab Judah, the division’s International Boxing Federation champion.

In a unanimous-decision win in December, Khan produced a gripping title defense by withstanding the best punches of hard-hitting Argentine Marcos Maidana.

The remarkable 10th round answered skepticism about Khan’s durability that date to a 2008 first-round knockout loss at the hands of British countryman Breidis Prescott.

“I’ve always wanted to prove all these people wrong,” said Khan (25-1, 17 knockouts), who proceeded to defeat Paul McCloskey by a technical decision in April. “I proved so much in that [Maidana] fight, giving and taking shots. I’ve proven I’m a different fighter at 140 pounds than I was at 135 [versus Prescott], when I was killing myself to make weight. I love 140.”

Khan and Judah each weighed in Friday at the limit, 140 pounds.

Khan was positioned to unify the weight class with a date against World Boxing Council champion Timothy Bradley, but the unbeaten Coachella Valley fighter declined Khan’s efforts to share in U.K. pay-per-view profits that would have pushed Bradley’s purse beyond $1.5 million.

Bradley, coming off a January victory over a sluggish formerly unbeaten Devon Alexander in Detroit, is embroiled in a nasty split with his promoters Gary Shaw and Ken Thompson.

Instead of following through on HBO’s plan to match the Bradley-Alexander and Khan-Maidana winners, Bradley is fighting a lawsuit by Shaw and will probably pay a settlement to resume his career.

That drama left Khan to act quickly on a replacement, and the 33-year-old Judah (41-6, 28 KOs) got the fight. Judah claimed his belt with a November split decision over Lucas Matthyse, then retained the title with a savvy technical knockout of Kaizer Mabuza in March.

“Zab does set traps — him going to the corner or ropes isn’t because he’s tired,” Khan trainer Freddie Roach said. “He’s tricky, he hides that left and you’ve got to keep from walking into it. He’s smarter than Amir because he has more experience. You can’t teach experience.”

Judah has spent the last decade fighting opponents such as Kostya Tszyu, Floyd Mayweather Jr. and Miguel Cotto. He lost those bouts and clearly needs success Saturday to continue to participate in big fights.

“I’ve been before the bright lights before,” Judah said. “He’s never been there against someone like me.”

Like Roach’s star fighter, Manny Pacquiao, however, Khan gets passionate when the subject is chasing personal greatness in the ring. He says he will top the Maidana effort by “knocking Judah out. … I know it’ll come. I’ll win in a good style. Judah can’t keep up with my power and speed.

“I know one bad performance can take all the good ones away. If I lose, people will say I’m just a normal fighter. I’m getting better. Bradley knew it. So he can wait. … It might be a bigger fight next year, but I’ll win that fight.”

lance.pugmire@latimes.com

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